Individual Supply Source

State Reservoir System

The CaDC Supply Explorer visualizes storage levels for all reservoirs in California over the last 5 years using data from the California Data Exchange Center, operated by the Department of Water Resources.


  • Click on the time slider at the bottom of the map to play an animation of reservoir levels over the last 5 years. Yellow bubbles indicate total reservoir capacities and blue bubbles indicate reservoir storages.

  • Click reservoirs to explore water storage over time, including daily historical averages for each reservoir.

  • Click the calendar icon above to select a date and see total statewide storage on that date.

  • To download source data, use the Download Data menu at the top of the tool.

This tool and underlying data data infrastructure has been designed, developed and deployed by ARGO in collaboration with Mike Amodeo, Vishwajeet Shelar, and Dongjie Fan as part of an agile feasibility study of the Dodd "Open and Transparent Water Data Act."